England scrum-half Ben Youngs believes defeat against Scotland in their Six Nations showdown at Twickenham would be a "disaster".

Martin Johnson's side are on course for their first Championship title and Grand Slam since 2003 following victories over Wales, Italy and France and while talk of the clean sweep is banned within the camp Youngs is not afraid to hold it up as a sign of England's ambition.

"Everyone is fully aware there is something special happening in the squad and if we play to our potential there is no reason we can't win the Grand Slam," Youngs told Press Association Sport. "It is a phrase we are not allowed to say! It is the target but if you know what obstacles are in your way you should be alright.

"We are fully aware of the threat Scotland pose. We are three from three but there are such big challenges ahead. If we lose this weekend it will be a disaster. It would end up being a shambles of a Six Nations because we have come so far. It would be like taking five steps forward and 10 steps back."

Youngs made his England debut off the bench as an emergency wing against Scotland a year ago in a miserable 15-15 draw at Murrayfield. Both he and the team have travelled a long way since. The highlight for Youngs was England's victory over Australia in Sydney, in which he scored his first Test try, but he is convinced bigger and better memories lie ahead.

"Things have happened very quickly. I have only been here for a year but I have never felt anything like the atmosphere in the squad," said Youngs. "It is just really exciting if you look how far we have come in the last year, from playing negative kicking rugby to playing with flair and ambition.

"The performance at Murrayfield was awful and I was the only one with a smile in the dressing room. Everyone else had their head in their hands. We have come a long, long way. The whole squad now believes we do have something special and we can achieve things. Maybe in the past the squad almost felt they didn't have the players to do it.

"The belief in the squad and the attitude to succeed is the main thing in the squad.
"I never get away from the fact I am only here because of my hard work and the things I have to do to consistently play well. You don't ever want to slip and you do whatever you can to hold onto that shirt."

Scotland are without a win this year and they have not beaten England at Twickenham in Youngs' lifetime. "We expect a tough game but I think we have plenty in our locker to put them away," Youngs said. "You don't want to be dragged into the Scottish game, the mauling and brawling. It is a trap you can easily fall into and sides often do that. But we showed against France, when things didn't go well, we wrestled it back again and won the game. We have the artillery to change things at any time."